gms | German Medical Science

Objectives: It has been reported that the bone resorption may be associated with the poor outcome in patients with osteonecrosis of the femoral head (ONFH). However, there have been few reports describing detail information of the features of the born resorption using micro-computed tomography. The aim of this study was to investigate the relationship between degrees of bone resorption and characteristics of patients with ONFH.

Methods: We retrospectively investigated 20 femoral heads extracted from 20 patients with ONFH during total hip arthroplasty. The ratio of volume of bone resorption to that of femoral head, the frequent site of bone resorption and the degree of collapse (association research circulation osseous (ARCO) stage) were evaluated using micro-computed tomography. The area of osteonecrotic lesion including necrotic angle and depth was also measured using magnetic resonance imaging. In addition, the characteristics of the patients including age, sex, affected side, risk factor (corticosteroid intake or alcohol abuse) and period from the occurrence of pain to surgery were examined and their correlations with the total amount of bone resorption volume were analyzed.

Results and Conclusion: The mean ratio of volume of bone resorption to that of femoral head was 7.43 ± 5.54% (range: 0.89 - 20.27%) and bone resorption tended to be anterior area of the femoral head (anterior area 9.75%, central area 6.56%, posterior area 4.09%). The mean ratios of volume of bone resorption to that of femoral head in female patients and ARCO stage 4 were significantly higher than those in male patients and ARCO stage 3 (collapse < 3mm), respectively (P < 0.05 for both).

In this study, bone resorption of ONFH tended to be anterior area of the femoral head. There were significant correlations between the volume of bone resorption and sex or stage of ONFH.